using Microsoft.EntityFrameworkCore;
using PowderCoating.Core.Entities;
using PowderCoating.Core.Enums;

namespace PowderCoating.Infrastructure.Services;

public partial class SeedDataService
{
    /// <summary>
    /// Seeds maintenance records for all seeded equipment: historical completed records,
    /// upcoming scheduled records, and one overdue record for the Pressure Pot so the
    /// Equipment Maintenance report always has meaningful data.
    /// </summary>
    /// <remarks>
    /// <para>
    /// Each piece of equipment gets 2-3 completed historical maintenance records (up to
    /// 12 months back) plus one upcoming scheduled record. The Pressure Pot additionally
    /// has one overdue record (past due date, still Scheduled) to populate the overdue
    /// indicator on the Equipment page.
    /// </para>
    /// <para>
    /// Labor and parts costs are realistic for shop equipment maintenance, giving the
    /// Equipment Maintenance Cost report non-trivial totals from day one.
    /// </para>
    /// <para>
    /// Idempotency: bails early if any maintenance records already exist for this company's equipment.
    /// </para>
    /// </remarks>
    private async Task<int> SeedMaintenanceRecordsAsync(Company company)
    {
        var equipmentIds = await _context.Set<Equipment>()
            .IgnoreQueryFilters()
            .Where(e => e.CompanyId == company.Id && !e.IsDeleted && SeededEquipmentSerials.Contains(e.SerialNumber))
            .Select(e => e.Id)
            .ToListAsync();

        if (equipmentIds.Count == 0) return 0;

        var existingCount = await _context.Set<MaintenanceRecord>()
            .IgnoreQueryFilters()
            .CountAsync(m => equipmentIds.Contains(m.EquipmentId));
        if (existingCount > 0) return 0;

        var equipment = await _context.Set<Equipment>()
            .IgnoreQueryFilters()
            .Where(e => equipmentIds.Contains(e.Id))
            .ToListAsync();

        // Try to grab a worker user to assign as performed-by
        var worker = await _userManager.Users
            .Where(u => u.CompanyId == company.Id && u.IsActive)
            .FirstOrDefaultAsync();

        var now = DateTime.UtcNow;
        var records = new List<MaintenanceRecord>();

        // Per-equipment maintenance spec: (type, daysAgoFirst, intervalDays, laborCost, partsCost, notes)
        // Each equipment gets 2 completed records + 1 scheduled upcoming.
        // The Pressure Pot also gets 1 overdue record.
        static (string type, decimal labor, decimal parts, string desc, string work)
            MaintSpec(int i) => (i % 5) switch
            {
                0 => ("Preventive",  120m,  45m, "Quarterly preventive maintenance",     "Inspected elements, cleaned contacts, checked gaskets"),
                1 => ("Inspection",   80m,   0m, "Monthly operational inspection",        "Checked all systems, calibrated temperature probes"),
                2 => ("Repair",      200m, 185m, "Filter and seal replacement",            "Replaced intake filters and worn door seals"),
                3 => ("Preventive",  140m,  60m, "Semi-annual preventive maintenance",   "Lubricated moving parts, replaced wear items"),
                _  => ("Inspection",  60m,   0m, "Pre-season inspection and cleaning",   "Full operational test, cleaned all surfaces"),
            };

        int idx = 0;
        foreach (var eq in equipment)
        {
            var isPressurePot = eq.SerialNumber == "CLM101223456"; // Media Blast Room / Pressure Pot

            for (int r = 0; r < 2; r++)
            {
                var (mtype, labor, parts, desc, work) = MaintSpec(idx + r);
                var daysAgo = 180 - r * 60 - (idx % 4) * 15;
                var scheduled = now.AddDays(-daysAgo);
                var total = labor + parts;

                records.Add(new MaintenanceRecord
                {
                    EquipmentId   = eq.Id,
                    MaintenanceType = mtype,
                    Status        = MaintenanceStatus.Completed,
                    Priority      = MaintenancePriority.Normal,
                    ScheduledDate = scheduled,
                    CompletedDate = scheduled.AddDays(1),
                    PerformedById = worker?.Id,
                    AssignedUserId = worker?.Id,
                    Description   = desc,
                    WorkPerformed = work,
                    LaborCost     = labor,
                    PartsCost     = parts,
                    TotalCost     = total,
                    DowntimeHours = 2m + r,
                    CompanyId     = company.Id,
                    CreatedAt     = scheduled.AddDays(-7)
                });
            }

            // One upcoming scheduled record
            var upcomingDays = 15 + (idx % 30);
            records.Add(new MaintenanceRecord
            {
                EquipmentId    = eq.Id,
                MaintenanceType = "Preventive",
                Status         = MaintenanceStatus.Scheduled,
                Priority       = MaintenancePriority.Normal,
                ScheduledDate  = now.AddDays(upcomingDays),
                AssignedUserId = worker?.Id,
                Description    = "Scheduled preventive maintenance",
                LaborCost      = 0m, PartsCost = 0m, TotalCost = 0m,
                CompanyId      = company.Id,
                CreatedAt      = now.AddDays(-7)
            });

            // Overdue record for the pressure pot only
            if (isPressurePot)
            {
                records.Add(new MaintenanceRecord
                {
                    EquipmentId    = eq.Id,
                    MaintenanceType = "Repair",
                    Status         = MaintenanceStatus.Scheduled,
                    Priority       = MaintenancePriority.High,
                    ScheduledDate  = now.AddDays(-20), // overdue
                    AssignedUserId = worker?.Id,
                    Description    = "Filter replacement — OVERDUE",
                    Notes          = "Media filter became clogged ahead of schedule. Shop is running reduced blast capacity until repaired.",
                    LaborCost      = 0m, PartsCost = 0m, TotalCost = 0m,
                    CompanyId      = company.Id,
                    CreatedAt      = now.AddDays(-30)
                });
            }

            idx++;
        }

        await _context.Set<MaintenanceRecord>().AddRangeAsync(records);
        await _context.SaveChangesAsync();

        return records.Count;
    }
}